I am very inexperience but really enjoy electronics work. I am learning very slowly. I recently encountered a television that won't stat up. When plugged in on Capacitor 100uF 250 volt is squealing continually. Is it fair to assume that capacitor is defective?

Capacitors shouldn"t make any noise at all so I don"t think that is the problem .....

I recently had a 36in RCA CRT TV set start squeeling really badly and it had no picture and it ended up that the Flyback transformer shorted out which caused the Picture to not work which also blew out a Power Mosfet in the switching PSU ...It cost me about $150 to fix and is still working fine......

TV sets are pretty complicated devises , much more complex than yer typical amp and a TV set has Voltages in it that can kill you pretty quickly , possibly even when not plugged in .... I would take it in to get fixed....

After doing a bit of research for you it turns out Power supply caps in switching power supplkies can make this noise when they get leaky.... Try replaceing it... I know in my TV the Big power supply cap in the SMPS was a Bi-Polar cap so if your is the same make sure you replace it with a Bipolar cap...